Summary of Current Site Knowledge Part B: Environmental Outcomes Part C
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RIVER ITCHEN SAC ROC STAGE 4 SITE ACTION PLAN : WATER RESOURCES PART A, B AND C - OCTOBER 2007 SECTION 3. WATER RESOURCES PART A: SUMMARY OF CURRENT SITE KNOWLEDGE PART B: ENVIRONMENTAL OUTCOMES PART C: OPTIONS APPRAISAL 1 RIVER ITCHEN SAC ROC STAGE 4 SITE ACTION PLAN : WATER RESOURCES PART A, B AND C - OCTOBER 2007 PART A. WATER RESOURCES This section of the document covers water resource permissions (abstraction licences) – the in- combination assessment of water resource and water quality permissions is set out in Part D. The material presented here comprises text with some supporting Tables and Figures. More detailed Tables and descriptions of the supporting data and technical analyses are provided in separate Water Resources Appendices (A to E). Whilst the outcome of Stage 3 has strongly influenced the approach to Stage 4, there are some important differences in the underlying principles which are incorporated into the guidance for Stage 4 (Ref: HD Work Instruction 184_01, Version 4, Issued 11th July 2005) that evolved over the course of the work presented in this document. The introduction to Chapter 7 of the guidance (Section 7.0 – General Principles) states that: “A pragmatic approach is required with the application of risk assessment principles when the outcome is uncertain, but the precautionary principle is an integral part of the assessment under the Habitats Regulations.” This Site Action Plan (SAP) therefore seeks to reconcile the elements of a pragmatic approach, developed from knowledge of the current condition of the designated site and the available science, with the precautionary principle. This Stage 4 assessment has therefore followed a risk-based approach in which the risk to the status of the site or individual species has been assessed for a range of licensed abstraction scenarios. Where a high risk of adverse impacts has been identified, appropriate options for mitigating the risk have been examined. By this means licences have either been affirmed or modified such that the resultant flow regime gives rise to a “negligible” or, at most, “low” risk of adverse impact on site integrity or status of individual species. A.1.1 What is known about the site The Stage 3 Appropriate Assessment looked specifically at the issue of the interest features’ and sub-features’ vulnerability to changes to the natural river flow regime resulting from abstractions and other catchment management interventions. This drew heavily on the River Itchen Sustainability Study (RISS), which has again provided the basis for this Stage 4 Review of Consents Options Appraisal. RISS considered the impact of abstraction on SSSI interest features as well as SAC interest features. Within this Site Action Plan only the SAC features are specifically considered and the SSSI features are considered in the context of supporting the chalkstream biotope including typical species. The basis for the identification of the SAC interest features is as follows: Annex I habitats that are a primary reason for selection of the site: Water course of plain to montane levels with the Ranunculion fluitantis and Callitricho-Batrachion vegetation Annex II species that are a primary reason for site selection: 2 RIVER ITCHEN SAC ROC STAGE 4 SITE ACTION PLAN : WATER RESOURCES PART A, B AND C - OCTOBER 2007 Southern Damselfly (Coenagrion mercuriale) Bullhead (Cottus gobio) Annex II species present as a qualifying feature, but not a primary reason for site selection: White-clawed crayfish (Austropotamobius pallipes) Brook lamprey (Lampetra planeri) Atlantic salmon (Salmo salar) Otter (Lutra lutra) A key conclusion of Stage 3 was that a range of measures relating to issues other than abstraction would be required if favourable conservation status is to be maintained (or restored). In other words, reducing the risk of adverse effect from abstraction from moderate to low or negligible would not necessarily be a sufficient step on its own. This is particularly relevant with regard to the conservation status of salmon and crayfish interest features. Recommendations for action are presented in Part G. For a more extensive summary of “what is known” about the site, reference should be made to the Stage 3 Appropriate Assessment (available upon request to the Environment Agency) and supporting reports. 3 RIVER ITCHEN SAC ROC STAGE 4 SITE ACTION PLAN : WATER RESOURCES PART A, B AND C - OCTOBER 2007 A.1.2 Summary of Stage 3 conclusions. Total No. of No adverse No adverse No adverse Others Agency effect on site effect on site effect on site permissions integrity can integrity integrity Licence Type assessed in be shown cannot be cannot be Stage 3. shown alone shown in- combination Group 1 9 5 4 Spray Irrigation Group 2 13 3 3 10 Watercress Group 3 13 3 4 10 Fish Farm Group 4 1 1 1# Industrial Group 5 7 7 Public Water Supply Group 6 2 2 2 Augmentation Group 7 0 Agriculture 3 3 Off Site Licences 48 14 9 34 1 Total Table A.1.2.1 Summary of the Stage 3 conclusions # Industrial Licence 11/42/22.10/119 has subsequently been surrendered 4 RIVER ITCHEN SAC ROC STAGE 4 SITE ACTION PLAN : WATER RESOURCES PART A, B AND C - OCTOBER 2007 A.1.3 New information since Stage 3 Since the Stage 3 Appropriate Assessment was published in February 2005, the Environment Agency has produced two fundamental guidance documents: Habitats Directive:Work Instruction (Chapter 7). The Review of existing Permissions, Plans and Projects (11/07/05) Work Instruction (Appendix 4) Stage 4 of the review of existing Water Resources permissions under the Habitats Regulations In addition to this core guidance, a supplementary operational instruction was issued in November 2005 entitled “Use of the resource assessment and management (RAM) framework on rivers designated under the Habitats Directive”. This guidance considered the use of RAM on riverine SACs in Stage 3 of the review of consents process. RAM was completed in the River Itchen SAC Appropriate Assessment but the Habitats Directive version of the spreadsheet was not available at the time that the work was completed. Within Stage 3, it was considered that better science lead to the development of a more site specific impact assessment and RAM was not the fundamental decision making tool. Since that time, the HD version of RAM was used within the Environment Agency’s Test and Itchen CAMS Ledger which was produced to support the Test and Itchen Catchment Abstraction Management Strategy (CAMS) published in March 2006. The conclusions of the HD RAM do not affect the conclusions of the original Appropriate Assessment and in a similar way to the stage 3 work, more detailed science has been used in stage 4 and RAM has not been the fundamental decision making tool. The Test and Itchen CAMS used the same Management Units as those used in RISS and the results confirmed that the Lower Itchen (RISS Management Units 5 & 6) is defined as Over Abstracted and the upper Itchen ( RISS Management Units 1 – 4) is broadly defined as Water Available which has been overridden by the downstream status to No Water Available. According to the operational guidance, this indicates that the ecology of the river could be under stress from abstraction and that there is a high risk to the integrity of the interest features. The guidance confirms that further investigation and examination of site specific data will be needed to draw conclusions of actual impact. It is this further investigation which is explained below. Whilst no new data have been collected in Stage 4, the rationale for decision-making in Stage 4 has been informed by a more robust assessment, analysis and interpretation of existing data than was possible in Stage 3. Key components of the Stage 4 work included: an extensive review of the documents issued at the conclusion of the RISS and the Stage 3 Appropriate Assessment (much of which was developed out of the RISS work); a series of consultation meetings with key participants and/or stakeholders in the Stage 4 process, including Natural England and relevant technical specialists; further use of the salmon entry model used in RISS and Stage 3 and additional integration of the outputs from the model with other available data; 5 RIVER ITCHEN SAC ROC STAGE 4 SITE ACTION PLAN : WATER RESOURCES PART A, B AND C - OCTOBER 2007 for the upper river, further development of the invertebrates assessment (by Agency staff) used in RISS and Stage 3 and the development of revised “target” regimes; for the lower river, the combined use of the invertebrates assessment and the salmon entry model to devise an appropriate “target” flow regime; and “testing” of the two approaches to future water resource management in the Itchen in the light of the Stage 4 guidelines. Further assessment of the impact of non consumptive licences such as fish farm and watercress licences Further assessment of the requirement for fish screens on surface water abstractions Further assessment of the Environment Agency’s Augmentation Schemes This new information has informed the development of Stage 4 Environmental Outcomes and the options appraisal process and is described further in those sections of the document and in the following Water Resources Appendices; Appendix A River Itchen Macro-Invertebrate Community Relationship to River Flow Changes. Environment Agency Report. Kevin Exley, February 2007. Appendix B Development of a Stage 4 Target Flow Regime, Atkins, March 2007 Appendix C Hydrology and Water Resources, Atkins, March 2007 Appendix D Non consumptive licences, Environment Agency,